BASIC MEDICAL SCIENCES

8) What is the most sensitive laboratory diagnostic tests for Chlamydia pneumoniae?
a) Giemsa staining test
b) Microimmunofluorescence test
c) Cell culture method
d) None of the above

9) Human is the only reservoir of Chlamydophila pneumoniae, the pathogen is most prevalent in which age group of people?
a) 2 to 5 years
b) 10 to 30 years
c) 5 to 18 years
d) 20 to 45 years

10) Name the organism given below which is frequently associated with urethritis apart from Chlamydia trachomatis?
a) Klebsiella pneumoniae
b) E. Coli
c) Streptococcus agalactiae
d) Neisseria gonorrohoea

11) All of the statements given below are correct about pathogenic Chlamydophila pneumoniae, EXCEPT?
a) It causes respiratory infections which is most common in young children
b) The bacteria spread from person to person via a respiratory route
c) It produces intracytoplasmic inclusions that lack glycogen
d) The infections caused by the bacteria are usually asymptomatic

12) When do the symptoms of neonatal pneumoniae in babies start to show caused by Chlamydia trachomatis?
a) In 1 week after the birth
b) In 2 to 12 weeks after birth
c) In 5 to 10 days after the birth
d) In 2 to 3 weeks after the birth

Multiple Choice Answers Review
1- Option b, c, and d are correct
2-a) Serotypes D to K
3-Option a, b, c & d
4- d) Within 7 to 15 days
5-b) Only Chlamydia trachomatis have specific antigens
6-a) They are seen on Gram stain
7-d) It only infects birds like parrots and cockatoos
8-b) Microimmunoflourescence test
9-c) 5 to 18 years
10-c) Neisseria gonorrohoea
11-a) It causes respiratory infections which is most common in young children
12-b) In 2 to 12 weeks after birth

14) The activated T cells undergo activation-induced cell death (AICD). Which of the following is the effector molecule that is a response for AICD
a) IL-2
b) Fas/Fas ligand
c) IL-4
d) INF-γ

15) T-cell receptor engagement with antigenic peptide MHC may induce T cell activation or the clonal anergy. Which of the following interaction favors T cell activation
a) Fas/Fas ligand
b) B-7 & CTLA-4 interaction
c) B-7 & CD28 interaction
d) B-7 & CD 8 interaction

Multiple Choice Answers
1-c) Bone marrow
2-d) None of the above
3-b) CD44
4-d) commit T cells for CD4 or CD8 positive T cells
5-d) All of the above
6-c) Both A and B
7-d) All of the above
8-a) Lck
9-c) Both
10-b) IL-2
11- a) T helper 1 CD4+
12-b) T helper 2 CD4+
13- a) CD4+ CD25+
14-b) Fas/Fas ligand
15-b) B-7 & CTLA-4 interaction

11) The diagnosis of Lyme disease is done by two serological tests after the screening test shows positive result thus first confirmatory test is the ELISA, what is the second?
a) Western blotting assay
b) PCR
c) Immunofluorescent assay
d) Southern blotting assay

12) Which of the following spirochetes causes skin disease primarily to individuals who have dark skin color and is transmitted by direct contact or vectors such as fly?
a) Borrelia hermsii
b) Spirillum minor
c) Treponema pallidum subspecies pertenue
d) Treponema carateum

13) Which of the following pathogens cause sexually transmitted diseases?
a) Treponema pallidum subspecies endemicum
b) Treponema pallidum subspecies pallidum
c) Borrelia recurrentis
d) Borrelia hermsii

14) Which of the following statements is not correct about congenital syphilis?
a) The spirochetes are transferred from mother to fetus across the placenta
b) The early manifestations occur in children during the birth
c) Five to ten percentages of children develop cutaneous lesions
d) The infection can lead to stillbirth

15) What is the most likely pathogen related to rat-bite fever?
a) Leptospira interrogans
b) Borrelia hermsii
c) Treponema pallidum subspecies endemicum
d) Spirillum minor

Multiple Choice Answers Review
1-d) They are obligate aerobes
2-b) Treponema endemicum
3-c) It often shows a false positive result for syphilis
4-d) Hard chancre
5-a) Borrelia recurrentis
6-a) Borrelia burgdorferi
7-a) It is used to observe and detect thin spirochetes suspended in liquid
8-c) Spirillum minor
9-c) Giemsa stain
10)- b) Antibodies are tested against the serogroup antigens from acute or convalescent phase
11-a) Western blotting assay
12-d) Treponema carateum
13-b) Treponema pallidum subspecies pallidum
14-c) Five to ten percentages of children develop cutaneous lesions
15-d) Spirillum minor

3) Which of the following Haemophilus spp require both the X (hemin) and V (NAD) factors for its growth?
a) H. parainfluenzae
b) H. ducreyi
c) H. aprophilus and H. paraaprophilus
d) H. haemolyticus

4) Which of the following is NOT the virulence factors responsible for the pathogenicity of Bordetella pertussis, a gram-negative coccobacillus that causes “whooping cough”?
a) An Endotoxin
b) A fimbriae and hemagglutinin
c) A pertussis toxin
d) A tracheal cytotoxin

5) Which of the following bacteria is responsible for “Malta fever” in humans which is caused primarily by contact with animals or animal products?
a) Haemophilus ducreyi
b) Francisella tularensis
c) Brucella spp
d) Haemophilus parainfluenzae

6) Name the specific food when consumed by humans that can cause “malta fever”?
a) Unpasteurized milk or cheese
b) Uncooked cauliflower
c) Plums
d) Cranberry juice

7) …....................is aerobic, non-spore forming, coco bacillus and can be transmitted to humans through water, soil, animals, also through aerosols
a) Haemophilus influenzae
b) Brucella spp
c) Francisella tularensis
d) Neisseria gonorrohoea

8) Which of the following subspecies of Francisella tularensis is the most virulent for humans?
a) novicida
b) tularensis
c) holartica
d) mediasiatica

9) All of the following are the symptoms caused by the pathogenic Brucella spp, EXCEPT
a) Fever
b) Swollen lymph nodes
c) Abdominal and muscular pain
d) Lesions on eyelids

10) Which of the following is not the general characteristics of Haemophilus ducreyi?
a) Gram-negative coccobacillus
b) It grows well on standard chocolate agar
c) It requires X factor but not the V factor
d) It is susceptible to erythromycin

11) Name the antibiotics group which is commonly NOT used for the treatment of influenza caused by Haemophilus influenzae?
a) Third generation cephalosporins
b) Aminopenicillins with a beta-lactamase inhibitor
c) Chloramphenicol with ampicillin
d) Amoxicillin with penicillin

12) What is a Quellung reaction?
a) The capsule detection test
b) The serological antibody detection test
c) Direct antigen detection test
d) The bacterial motility test

13) The preventive measure for Bordetella pertussis infection is vaccination method, the pertussis vaccine is usually administered in combination with toxoids of Diphtheria and tetanus (DTaP). The pertussis vaccine is primarily important for children, preteens, pregnant women and adults who have never received it, what doses of this vaccine is recommended for children under six years?
a) Six doses of vaccine
b) Three doses of vaccine
c) Five doses of vaccine
d) Four doses of vaccine

14) .................... is the causative agent of the chancroid, one of the most common sexually transmitted disease and is characterized by painful lesions and genital ulcers?
a) Neisseria gonorrohoeae
b) Haemophilus haemolyticus
c) Haemophilus ducreyi
d) Treponema pallidum

15) Which of the following do not prove to be helpful for the treatment of whooping cough?
a) Cough syrups and expectorants
b) DPT vaccine
c) Macrolides
d) None of the above

Multiple Choice Answers
1-d) A, B and C
2-c) Haemophilus influenzae type b
3-d) H. haemolyticus
4-a) An Endotoxin
5-c) Brucella spp
6-a) Unpasteurized milk or cheese
7-c) Francisella tularensis
8-b) tularensis
9-d) Lesions on eyelids
10-b) It grows well on standard chocolate agar
11-d) Amoxicillin with penicillin
12-a) The capsule detection test
13-c) Five doses of vaccine
14-c) Haemophilus ducreyi
15-a) Cough syrups and expectorants

3) What is the mechanism responsible for antibiotic resistance in Mycobacterium tuberculosis?
a) Mutations in DNA gyrase gene
b) Alterations in beta-lactamase
c) Mutations in the catalase-peroxidase gene
d) Alterations in RNA polymerase

4) All of the following are the examples of selective media used for culture of Mycobacterium tuberculosis, except?
a) Inspissated egg media
b) Middlebrook 7H10/7H11 media with antibiotics
c) Dubos media
d) Middlebrook 7H10 media without antibiotics

5) Which of the following statement is true about the tuberculin test and purified protein derivative (PPD)?
a) The presence of intradermal skin induration is observed in 6 to 8 hours after being applied
b) The redness of skin or erythema is also measured while reading the tuberculin test
c) A positive tuberculin test means that a person was infected with M. tuberculosis in the past and continues to carry the viable organism
d) A positive PPD test indicates that a person can never be infected with M. tuberculosis

6) Which of the following is fast growing, non-chromogenic rod bacilli?
a) Mycobacterium ulcerans
b) Mycobacterium avium complex
c) Mycobacterium leprae
d) Mycobacterium fortuitum

7) All of the following are the symptoms of pulmonary tuberculosis, EXCEPT?
a) Weakness and fatigue
b) Decreased body temperature
c) Weight loss
d) Severe prolonged cough with sputum or blood

8) Which of these following categories of people do not require the test for TB infection?
a) A 30 years old man traveling from India to the USA for the first time
b) A 45 years old woman contradicted with HIV infection
c) A 7 years old healthy girl living together with her grandmother who has tuberculosis infection
d) None of the above

9) Which of the following bacteria causes lung infection and is the most common non-tuberculous mycobacterial infection associated with AIDS patients?
a) Mycobacterium avium complex
b) Mycobacterium leprae
c) Mycobacterium gordonae
d) Mycobacterium gastri

10) A 40 years old patient who has clinical symptoms pulmonary tuberculosis for the past two months. The chest x-ray examination revealed a typical feature of tuberculosis infection. A photochromogenic (orange pigment when exposed to UV light) acid-fast rod bacterium was isolated from the sputum sample. The identified bacteria is:
a) Mycobacterium avium
b) Mycobacterium tuberculosis
c) Mycobacterium kansasii
d) Mycobacterium leprae

11) All of the given are the distinguishing characteristics of Mycobacterium leprae, EXCEPT:
a) Acid-fast bacilli
b) cannot be isolated by in-vitro culture method
c) is a human and as well as animal pathogen
d) can be isolated by in-vivo culture method

12) Which one of the following acid-fast rod bacilli can take up to ten years for its growth in host cells and causes skin infections?
a) Mycobacterium tuberculosis
b) Mycobacterium avium complex
c) Mycobacterium leprae
d) Nocardia spp

13) Other than Mycobacterium tuberculosis which of the given bacteria causes tuberculosis infection in animals and can be transmitted to human by consumption of milk and other animal products?
a) Mycobacterium ulcerans
b) Mycobacterium leprae
c) Mycobacterium bovis
d) Mycobacterium abscessus

14) The treatment regimen for initial therapy of tuberculosis caused by M. tuberculosis includes?
a) Streptomycin and rifampin
b) Isoniazid, streptomycin, and ethambutol
c) Rifampin, isoniazid, and ciprofloxacin
d) Isoniazid, rifampin, pyrazinamide, and ethambutol

15) What is the interferon-gamma release assay?
a) The antigen detection test for the Mycobacterium spp
b) The DNA detection test in Mycobacterium spp
c) The test used as an alternative tuberculin skin test in latent tuberculosis
d) The test used as an alternative tuberculin skin test in active tuberculosis

Multiple Choice Answers Review
1-d) Both B and C options given above
2-b) Isoniazid and Rifampin
3-c) Mutations in the catalase-peroxidase gene
4-d) Middlebrook 7H10 media without antibiotics
5-c) A positive tuberculin test means that a person was infected with M. tuberculosis in the past and continues to carry the viable organism
6- d) Mycobacterium fortuitum
7- b) Decreased body temperature
8- d) None of the above 9-a) Mycobacterium avium
10-c) Mycobacterium kansasi
11-c) is a human and as well as animal pathogen
12-c) Mycobacterium leprae
13-c) Mycobacterium bovis
14-d) Isoniazid, rifampin, pyrazinamide, and ethambutol
15-a) The antigen detection test for the Mycobacterium spp

4) Which of the following is NOT the characteristic feature of T cell receptor
a) T-cell lineage Exclusivity
b) Affinity Maturation
c) The combinatorial joining of VDJ
d) Somatic hypermutation

5) Gamma/delta T cell receptors are present in a subset of T-cells and play role in unconventional recognition of antigens. All of the following statements are correct EXCEPT
a) The gamma/delta T-cell receptors are co-expressed with alpha/beta T-cell receptors
b) The gamma/delta T cell receptors undergo allelic exclusion when alpha/beta are expressed and vice versa
c) The gamma/delta T cell receptors recognize the phospholipid antigens
d) All of the above

6) Which of the following statement is true regarding the TCR gene organization and rearrangement?
a) The alpha & gamma genes consist of multiple variable (V), joining (J) and one constant gene
b) The beta & delta genes consist of multiple variable (V), diversity (D), joining (J) genes and one constant gene.
c) Both of the above
d) None of the above

7) Which of the following process contribute to the diversity of TCR?
a) Somatic hypermutation
b) Junctional flexibility
c) Genetic recombination
d) None of the above

8) Once the TCR binds to the pMHC, the signal transduction mediates the T cell activation via CD3 molecules. The CD3 molecules consist of
a) Delta & Epsilon heterodimer
b) Gamma and Epsilon heterodimer
c) Zeta homodimer
d) All of the above

9) The alpha/beta chain of TCR has three complementarity determinant regions CDR1, CDR2, and CDR3. Which of the following CDR binds to the antigen peptide?
a) CDR1
b) CDR2
c) CDR3
d) All of the above

10) Which of the following is NOT the function of the T-cell receptor
a) Antigen Recognition
b) Facilitate binding of co-receptor
c) Serve as the signal transducer
d) Induce signal transduction via a CD3 protein complex

11) Which of the following CD3 molecule is required for assembly of TCR-CD3 complex into the plasma membrane?
a) Gamma
b) Delta
c) Epsilon
d) Zeta

12) Which of the following protein of TCR/CD3 complex do not consist of ITAM domain required for signal transduction?
a) alpha/ beta chain of TCR
b) gamma/epsilon heterodimer of the CD3 complex
c) delta/epsilon heterodimer of the CD3 complex
d) Zeta homodimer of the CD3 complex

13) Which of the following subunits have three ITAM domains?
a) Gamma
b) Delta
c) Epsilon
d) Zeta

14) In addition to the TCR-CD3 complex, the T cell activation requires the engagement of co-receptors with the MHC of the antigen presenting cells. Which of the following co-receptor binds to MHC-I APC
a) CD4
b) CD8
c) CD20
d) None of the above

15) In addition to the TCR-CD3 complex, the T cell activation requires the engagement of co-receptors with the MHC of the antigen presenting cells. Which of the following co-receptor binds to MHC-II APC
a) CD4
b) CD8
c) CD20
d) None of the above

Multiple Choice Answers Review
1-a) protein of immunoglobulin superfamily
2-c) Both of the above
3-d) The variable region is present in the C terminal region of the TCR
4-d) Somatic hypermutation
5-a) The gamma/delta T-cell receptors are co-expressed with alpha/beta T-cell receptors
6-c) Both of the above
7-b) Junctional flexibility
8-d) All of the above
9-c) CDR3
10-c) Serve as the signal transducer
11-d) Zeta
12- a) alpha/ beta chain of TCR
13-d) Zeta
14-b) CD8
15-a) CD4